This invention relates to a towbar assembly in which two individual towbars are arranged in a V-configuration between the towing vehicle and the towed vehicle. The invention can be used in various vehicle environments. However, it was particularly devised for use on relatively heavy vehicles, such as military tanks weighing on the order of fifty tons.
Each individual towbar includes a tube constituting the major portion of the towbar length, and end connectors affixed to the tube ends. An aim of the invention is to design the end connectors on each towbar so that each towbar is substantially identically loaded, at least when the vehicles are moving in the straight-ahead direction. This is accomplished primarily by designing the front end connectors so that they can simultaneously fit onto a single towing pintle carried by the towing vehicle. Each front end connector is a flat plate having a circular opening therethrough sized to fit over the towing pintle; one face of the plate area surrounding the circular opening is transversely curved so that when the front end connectors on individual towbars are positioned on the pintle the noncurved flat plate faces mate together, while the curved faces engage the pintle surface in nonbinding fashion. The curved surface engagement between the towbar end connectors and pintle permits the towbars to swivel around the pintle in a side-to-side direction and also in a vertical up-down direction. The individual towbars are subjected to minimal load changes when the vehicles change attitude or direction.
A second aim of our invention is to design the towbar end connectors so that each towbar tube is loaded essentially in tension or compression, without any oblique loadings that would produce bending stresses in the tubes. By confining the towbar loadings to tension or compression loadings, it becomes possible to reduce the tube wall thickness and tube weight. For heavy vehicle situations, such as military tanks, the individual towbar weight is of some importance as regards to cost and effect on vehicle payload, as well as easier handling by an individual when making or unmaking the connections between vehicles. In battlefield situations, the time required to achieve towbar hook-up of a disabled tank to a towing tank may be an important consideration. We achieve towbar weight reduction by making each individual towbar separate from the other towbar, and also by the above-discussed end connector design for confining the loadings to tensile loadings or compression loadings.
A further aim of our invention is to simplify the towbar-vehicle connection mechanisms insofar as possible without having to completely redesign the attachment mechanisms used on existing vehicles, especially military tanks now in the field. Our towbar design is compatible with existing towing pintle-hook construction found on present U.S. Army tanks, e.g., the M-60 tank.